Confirmation message for exp/item cost

[DaveDevil]

Description of feature/improvement request:

Like it happens with money cost with specialized commands, it would be useful to have a confirmation in case of item or exp cost too

---

Detailed explanation of what it should do, when and in what situation:

• expcost:10! warp spawn [playerName]

"Are you sure you want to spend 10 Lvls to use command ?"
YES NO